The invention concerns a system for managing the movements of different parts of one or more vehicle seats.
The invention applies to numerous types of seats, such as motor vehicle seats, train seats or boat seats; it applies in particular to aeroplane seats.
At the present time, numerous types of vehicle seats exist with which it is possible to change the position of one of the seat parts relative to another seat part. In particular, aeroplane seats are all designed so that the passenger can be seated in a semi-lying position or in an upright sitting position (in particular for take-off and landing), or in intermediate positions. Traditionally, for aeroplane seats, the mobile parts of the seat are the back part, the leg-rest and the footrest, the seat part generally being fixed. These parts are often actuated relative to one another by a mechanical system or an electro-mechanical system, that is to say which is electrically controlled and mechanically actuated.
However, irrespective of the type of actuation, it is always necessary to have stops which limit the movement of the different parts, firstly to avoid damage to the equipment and secondly to ensure the safety and comfort of passengers. These stop parts are often mechanical. They may also be formed of end-distance sensors positioned at the ends of the actuating rod.
U.S. Pat. No. 5,887,949 describes an aeroplane seat in which the positions of the footrest and leg-rest are controlled so that the footrest does not hit the floor when the leg-rest changes from the lying position to the sitting position. In this device, position control is made by means of an end-distance sensor. These end-distance sensors, like the mechanical stops, are fixed to the seat either during the manufacture of the seat or at the time the seat is fitted in the aeroplane. However, it is sometimes necessary to change the position of a stop part or the limit value of an end-distance sensor once the seat has been installed, for example should the layout of the aeroplane require a change to the vertical position of a back part. In this case, the only possibility is to modify the limit value of the stop part on site. Consequently, if the stop parts of all the seats of an aeroplane have to be modified, this leads to considerable cost both in terms of time and of expense.
Moreover, a motor vehicle seat exists in which the position of the seat part and the position of the back part are calculated one in relation to the other, so that the overall position of the seat meets safety criteria.
For this purpose, the movements of the seat part and back part, one relative to the other, are controlled by electric motors and detected by potentiometers. This type of seat is described in patent application FR-A-2 736 879.
However, with this device the position of the seat part and back part are controlled in dependent manner in relation to one another. This device cannot therefore be adapted to a seat comprising numerous parts (head-rest, leg-rest, footrest, arm-rests, etc.), which may be moved independently from one another.
Document FR-A-2 748 240 describes a system for actuating seat parts, wherein each part is actuated by means of an actuator. The actuators of two adjacent seats are controlled by centralised processing unit, additionally connected to a keyboard or a card reader corresponding to each seat. Preregulated positions of the different seat parts can thus be memorised, between the end positions.
The object of the invention is precisely to remedy the disadvantages of the previously described devices.
For this purpose, it puts forward a movement management device for the different parts of a seat, in which each part may be moved dependently or independently from the others, according to the position wished by the passenger.
More precisely, the invention concerns a movement management system for the parts of at least one vehicle seat, which at each connection placed between a first and a second part of the seat comprises means for actuating the first part relative to the second part, associated with memorisation and control means of the end positions of each part, characterized in that it comprises memorisation and control means of the limit transmission forces of the actuating means of each part and a command unit connected to each of the memorisation and control means, said command unit being integrated in an actuation means.
According to one variant of the invention, the memorisation and control means comprise a potentiometric copying system of the end positions. According to another variant, they comprise an impulse system for position copying with re-locking.
According to one embodiment of the invention, the memorisation and control means comprise a copying system of limit transmission forces by current measurement.
According to another embodiment, they comprise a system for copying limit transmission forces which uses stress gauges.
According to a further embodiment, they comprise a potentiometric copying system of limit transmission forces.
Advantageously, the values of the end positions and the values of the limit transmission forces can be modified at the command unit.
The invention also applies to the movement management of several seats. In this case, the command unit of each seat is, by means of at least one bus, connected to the command units of the other seats and/or to at least one central unit. In this case, the values of the limit transmission forces and of the end positions may be modified from the central unit.